The present invention relates to sealed nickel-metal hydride storage cells and a hybrid electric vehicle having the storage cells.
Japanese Laid-Open Patent Publication No. 9-204931 discloses a sealed nickel-metal hydride storage cell that has positive and negative electrodes containing nickel and hydrogen-absorbing alloy, respectively, as active materials. In order to avoid an increase in cell internal pressure and allow a reduction in cell size, weight and production cost, the quantity of electricity stored in the storage cell after the completion of charging is set smaller than the theoretical capacity of the positive electrode.